IN 1968, my cousin Jim and I pushed through the decadent art deco doors of Paisley's Kelburne Cinema, with the taste of excitement in our mouths.

This was not just in anticipation of the Kia Ora and crème egg combination we were set to enjoy. We were about to watch Carry On Up The Khyber, the 16th in the series of comic misadventures, and one hour and 28 minutes later we weren’t disappointed. Oh, how two 12-year-old schoolboys laughed at the daft plot as the 3rd Foot and Mouth Regiment took on the Afghan Burpa tribe. How we chuckled at the absurd character names, such as the waspish Kenneth Williams’s Khasi of Kalabax, and Cardew Robinson’s The Fakir.

Now, 42 years on, it’s been revealed the Carry On movies are to carry on with screenings of the originals and two new movies, Carry On Doctors and Carry On Campus to be made. But why were the Carry Ons so successful in the first place, landing in our faces more often than Barbara Windsor revealed her bra to the world?

Jim and I had no theory at the time, except that we thought them funny, but our pubescent minds, it seems, were processing more than the silliness, the puns, the innuendo and the predictable set-up and sight gags which ran to formulae.

What we didn’t realise was that the Carry Ons had arrived in the wake of the kitchen sink dramas of the 1950s and early 1960s, and movies such as Saturday Night, Sunday Morning, which mirrored society's mores, throwing audiences’ lives right back in their faces. The underlying theme of the kitchen sinkers was sex, or rather the prohibition of it in the pre-Pill era. In films such as This Sporting Life and Alfie, men couldn’t have any without marriage, while women were defined by the compromises they had to make.

What the Carry On films did was carry on with this theme, but the sexual frustration was given a comedy backdrop and a variety theatre sensibility. The early Carry Ons worked because they captured the mood of the period, the emotionally confused zeitgeist.

Jim and I were still reading the Hotspur at the time so we didn’t quite grasp that the Carry Ons had tapped into Freudian theory, which explains the psycho-social relationship between sexually inhibited male desire and censorship. We had little realisation that frustrated virgins in the audience were watching themselves up there on screen, as indeed were the married men, particularly those who felt trapped by marriage. The repression we felt, but didn’t quite comprehend, was represented by phallic symbolism and nudge-nudge gestures. Nor did we grasp that to underline the theme, the characters were drawn in thick black ink: the men as sex-starved inadequates and the women as either coquettish tease-pots or chastity belt-wearing dragons.

Nor did we realise that the series’s writers (the same seven were used consistently over a 20-year period) knew exactly what they were doing in terms of scripting the psychological dilemmas being played out.

Films such as Carry On Sergeant, Carry On Teacher and Carry On Cruising all featured psychoanalysis as a sub-plot. In Carry On Matron, Doctor FA Goode (Charles Hawtrey), is the resident psychiatrist who hypnotises himself with his own watch, and in 1964’s Carry On Spying, the evil Doctor Crow (Judith Furze) uses hypnosis to create the ultimate "being with the characteristics of both sexes" – by manipulating people's minds.

Many of the Carry On storylines in fact feature men who can’t make love to their wives or get enough sex. And many of the laughs these stories generated were recognition laughs. Yes, the women are written through the prism of sexism, there’s certainly a pre-feminist agenda, but the men were the real butt of the jokes, all too often flops who wouldn’t know what to do with a lady. In Carry On Sergeant (1958) for example, when Horace (Kenneth Connor) is told to strip down to his underwear for examination, he runs back out clutching his trousers to his breast and screaming: "Why didn't you warn me?" His terror? Recruitment officer Captain Clark had turned out be Hattie Jacques, every inch a woman.

There was even more psychological manipulation of the audience going on than the two little crew cuts in the back row could have realised. We’d seen Carry On Cleo (1964), and laughed when Kenneth Connor’s character couldn’t make love to his domineering wife because she reminded him of his mother. But of course we had no idea of the Oedipal trajectory of the narrative.

Yes, the Carry Ons weren’t always clever; sometimes they were simply sexist, but very often, women won out. In Carry On Up The Jungle (1970) the women were empowered. Sort of. The Amazonian-like members of the Lubby-Dubby tribe of course had to look like Raquel Welch in One Million Years BC in their fur bikinis, but nevertheless, they were in control of society. They chose the men they bred with, and the men failed to satisfy these gorgeous creatures. And teenage boys laughed at this because if we weren’t enjoying the delights of carnality, why should they?

The punch line was perfect. The only man who could make these awesome women happy was little, weedy, Tonka The Great, played by Hawtrey, giving hope to every weedy man and boy in the audience, which represented most of Scotland at the time.

But there was more to the early Carry Ons than having fun at the expense of the frustrated male. What the films did very cleverly was attack, via parody, British institutions and cultural outlets. The Brits love nothing more than laughing at themselves, pulling down the underpants of authority – in public – and giving it a good skelp on the behind, and so Carry On Sergeant lampooned the Armed Forces, Khyber was an attack on the Raj, Carry On Doctor laughed at the middle-classness of the medical world and trade unions were flushed down the toilet in Carry On At Your Convenience.

The Carry Ons also sent up the world of camping, beauty contests and caravan holidays and took a surgical scalpel to Hammer Horror films in Carry On Screaming.

Carry On Henry (1971) even had a right good go at the monarchy and its sense of privilege. It’s all a bit prurient when King Henry (Sid James) is out hunting on horseback and chases a peasant girl into a barn as if she is literally a "game" bird, but the audience can also mock this smug sense of Royal entitlement.

Were the Carry Ons funny? In bits. Yes, there were lots of tedious gags lines such as: "Look in on Mrs Bottomley at No 24. She's complaining of suspicious activities in the rear of her premise."

And some very outrageously sexist. Even Jim and me cringed a little watching the scene in Carry On Doctor in which the doctor examines a voluptuous young girl with his stethoscope.

"Big breaths," he commands.

"Yes and I'm only 16,” says the girl.

Yet some, in fact many, jokes assumed audience intelligence and erudition. In Carry On Cleo, Williams plays Julie Caesar (a nod to the actor’s homosexuality) and when someone bangs a gong, Williams quips: "Rank stupidity!"

But who didn’t laugh at the line in Carry On Camping when Mr Muggins the hitchhiker (Hawtrey) comes across a young farm girl leading a cow down a lane.

“I say, what are you doing with that old cow?”

“I'm taking her to the bull.”

“Oh, couldn't your father do it?”

“No, it has to be the bull.”

This reminds us of the strength of the acting. Sid James and Kenneth Williams (fresh from Hancock success) had immeasurable talent, Hattie Jacques was commanding yet fragile, Joan Sims endearing and Barbara Windsor made to play the dolly bird. Bresslaw and co, (with some exceptions such as Terry Scott) revealed they could all play grotesques. And Carry On offered great panto-esque moments in which the likes of Hawtrey and Williams don’t just break the fourth wall, they smash it to pieces.

What should also be commended is the fact the Carry Ons helped keep the British film industry alive, making 31 movies between 1958 and 1992, overspilling into TV series and theatre shows. And they were all made for less than a TV football pundit’s annual salary, shot at Pinewood Studios in Buckinghamshire, with "location" shots cleverly using the hills of Snowdonia, for example, as the Khyber Pass. It didn’t matter if we could see the obviously-placed tropical plant pots and sand pits. We, the audience, were in on the joke.

But Jim and I became bored of the Carry Ons. By aged 13, we’d moved on from soft, schoolboy Crème Eggs to Mars Bars, and our Kia Oras were now being slurped during screenings of more racy, obvious soft porn in the form of the Confessions films (in which congress was actually being achieved) in which Robin Asquith’s backside was cheekily bared to the world. The Carry On storylines seemed hackneyed (although we didn’t know that word at the time).

Certainly by 1974 and Carry On Dick (which looked as though it had been written by Bernard Manning) and the subsequent soft porn parody Carry On Emanuelle (1978), the fun of sexual frustration had long gone.

We no longer viewed marriage as imprisonment, and the arrival of the Pill changed the fabric of society, offering choice to women and men.

In 1992, a new attempt was made to feed the franchise filmic Viagra in the form of Carry On Columbus, but it was a box office flop.

Will a new Carry On carry it off? It seems unlikely. Producer Jonathan Sothcott of Hereford films has described Carry On as "a national treasure: the most successful British comedy film series of all time, adding: "But this isn’t a remake or an attempt to reinvent the wheel.”

What is it then? New British comedy films with a Carry On title stuck on to sell tickets? And if the originals worked because they captured the sexual containment of the time, what will define the sensibility of the new efforts?

The gender divide is captured continually – and cleverly – in modern British TV relationship comedy, with the likes of the Inbetweeners and Pramface. The battle of the sexes is well played out in Lee Mack’s Not Going Out. So where is the market for Carry On-like titillation? These days young men (the core Carry On audience was male, aged seven-28) are brought up on Babestation and Kim Kardashian’s home movies. They don’t have to wait an hour and a half in the hope of seeing Babs Windsor’s bits. Carry On seaside postcard humour just ain’t worth writing home about.

There is a comedy area to be mined perhaps in the modern-day feminisation of men, but will the deft hand of a comedy writer be employed to carry that off? Not a chance. Will the new producers return to sending up today's cultural establishment and institutions? Will we have Carry On Up Your Eurotunnel? Carry On Trumping? Carry On Jihadist? Ha. There’s more chance of Sid James coming back from that great Carry On lot in the sky. (Anyway, Chris Morris has already attempted the latter with the very clever 2010 film, Four Lions.)

What you suspect is that the new Carry Ons will be rather sad attempts to capture a film series that was of a very different time, another era, another world in fact. And that’s where Sid and Babs and Kenneth and Charles should remain.